Relationship between cognitive decline and depression in patients with Parkinson’s disease

Abstract

The aim of this study was to assess the cognitive decline in patients with Parkinson’s disease and to study its correlation with their depression. We studied 64 consecutive patients (30 men and 34 women), mean education level 11.2±1 years and mean age 72.3±3.5 years. These patients were admitted to Clinic of Neuropsychiatry Craiova between January 2016 and October 2016. They underwent a neurological and neuropsychological examination at baseline, after 6 months and 12 months later. For the cognitive assessment we used the revised version of the Addenbrooke′s Cognitive Examination (ACE-R) and Montreal Cognitive Assessment (MoCA) and for the evaluation of depression we used Hamilton Depression Rating Scale (HDRS). We have also included in our study a control group composed of 76 control subjects with the same range of educational level and age. All the patients met the diagnostic criteria for Parkinson′s Disease. In this study we included patients in stage I and II on Hoehn and Yahr scale. Twenty-six patients were in stage I and 38 patients in stage II. The patients were treated with levo-dopa monotherapy, dopaminergic agonists monotherapy, or levodopa associated with dopaminergic agonists. At baseline the patients in stage I showed a mean MoCA score 26.8 and a mean ACE-R score 89.6. The patients in stage II had a mean MoCA score 26.5 and a mean ACE-R score 89.4 at baseline. The control subjects showed a mean MoCA score 27.06 and a mean ACE-R score 90.3. One year later the patients group I showed a mean MoCA score 19.8 and 84.7 mean ACE-R score. The groups of patients in stage II had a mean MoCA score 18.3 and ACE-R score 84.2. The control group the mean MoCA values was 22.56 and ACE-R 87.1. Regarding assessment of depression, we obtained the next scores: at baseline, patients in stage I showed a mean HDRS score of 14.6; the patients in stage II a mean HDRS score 14.8 and the control group a HDRS mean score of 8. One year later group I showed a mean HDRS score of 18.8; the group II 19.9 and the control group 9.7. For the statistical analyze, we used Student test (p<0.05 statistically considerable). The patients with PD showed a greater cognitive impairment and depression than the control subjects. We observed that the patients in stage II Hoehn and Yahr had a greater cognitive decline and depression than patients in stage I. Depression was diagnosed in 40 patients at 6 months and in 56 of the patients at 12 months. The cognitive impairment was higher at 12 months than at 6 months. The depressive patients had more severe cognitive decline than the nondepressive patients.

Keywords

• cognitive decline
• parkinson’s disease
• depression